Valve lead control for valve gear mechanism



May 31, 1932. A COTTON VALVE LEAD CON'EROL FOR AVALVE GEAR MECHANISM Filed Feb.' 14, 1929 4 Sheets-Sheet l May 31, 1932- J. A. co'r'roN VALVE LEAD CONTROL FOR VALVE GEAR MECHANISM 4 Sheets-Sheet 2 Filed Feb. 14, 1929 w, WA. ww .w

May 31, 1932- J. Ak coTToN VALVE LEAD CONTROL FOR VALVE GEAR MECHANISM Y 4 Sheets-Sheet 3 Filed Feb. 14. 1929 May 3l, 1932. .1. AfcoTToN `VALVE LEAD CONTROL'FOR VALVE GEAR MECHANISM 4 sheets-sheet 4 Filed Feb. 14, 1929 l" Q Jol/x7 A. Guitar,

Patented May 31, 1932 -JoHN ;A..\ .corroN, or `cALGAivsr, ALBERTA.' CANADA VALVE LEAL coNfrnoLroR VALVEGEAB. MECHANIS.if;` p

' A3i1icetion-fnedretruery 14,1929, serial NO 'Seem-gfandlin canadarebrvuaryfaa 1929. t

`The invention 1Vrelates to :improvements in valve'lead :control forvalve gear mechanismV and 'more particularly to valve mechanism forlocomot'ives and especially totha-t type-of locomotive equipped witlithe welll known W'alschaer't 'valve gear; y

AAri-object of the invention is vto pr'ovid'el-a valve gearf construction that-will positively insureth'at the locomotive will'start when'lthe lo reversing gear is-fmovedtoeither of its eX- treme forward or back positions, such being brought about by'supplying a steamdi-stribution in the right and left'enginecylinders and controlled bythe steam valves to give a mairi-V s mum starting effort. A, y VIn theaccompanying, drawings, wherein my inventionappears-as utilizedin the VVals'- chaert-valve gear,vv Y

' F'gkl "s aiview" Showing the VValschaert 20 valve-gear with vmy inventionintroduced,v andthe parts in the positions occupied when the locomotive is to bestart'ed'." QV

Fig. 2i's'a viewsimilar to Fi'gu-rel with-the Various parts shown astheyappear in a run'- '.25 ning condition ;ofx.theA locomotive,: 'the main' Crank LPD Tbng Shown in fthe samel position as selected Figure 1. f

Fig.y Sis` an enlarged vertical sectionalview Fig. 4 is a horizontalfsectionalview at @le-4 Figure lwith the sliding 'linkblock raised to bringthe pin thereofV into alignmentwith the trunnions'of the side plates. y Fig. "5. i's an enlarged detailed plan View of -35 the control link andassociatedparts.

Fig'. 6 is an enlarged vertical sectional view atjG-"-6"Figure 1. Y

Fig. -7A `s aperspective view; of the parts appearing in Figure 6,"portions being broken 4o away to ,expose construction.

f Fig. Siisaview showing diagrammatically variouspositions of the valve in relation to the rvarious 'postions lof'the main driving crankl pin7 the reversin'ggear` being -set in *is the position occupied; when moved to start the locomotive. f s 4 I Adfn-the drawings like characters ofi-eferencein'dicate lcorresprpnding parts in Lthe several iiguresl@ so AS before intimated, i. `im@show-mynl.l

and this arm'ispivotallyy connected tothetoe l 6 of themotion link 17. The motionlink presents' as;is l"usual an' elongated arcuate slot 7=slidablyreceivingthe link. block 8 `and the Y link block is carried by a cross pin Vr9 f supported by the forked rear extremity vof the radius rodlO.l Theimotionflink is attached -f by suitably locatedand spaced, upper and lower` :sets of pins to nside plates 8 'andi` 8 spaced from the inner a'ndr'outer` sides of1 the link block. V'lhepla-tes :carry axially aligned trunnions 82`vvhich1are rotatably mountedin fined side bearingsfSa `permanently:fastened to lan adjacent Xedi part locomotive l The rear end of the ,radius rod `1.0= isV con; nectedpifvota'lly to theback radius rod hanger 11 which .in turn isl pivotally` attached'to' the rearend ofthe lower tumbling shaft arm12'.

The said tumbling :arm lis permanently fa's.- tenedto 'one end of the .tumblingshaft 13', this shaft passing across from? oneside of 'the locomotive to they otheinf 'Tli'eftumbling' shaft `is counterbalanced by weight/lgfprovided and it is. also suppliedv with an'v upstanding arm `145 'whi ch is"v connected f pivotally tothe forward end ofi-the reach ro'd. which latter rodwis directlyconnected in' the' cab `in 'the usualmanner to the conventionalreversing 7 Y lever (not shown) The Vengine cylinder `-18 contains fthecus'i l tomarypisto'n 1'8"havin'g the extending 'connecting rod 19 thereof rearwardly? attached Y carries-a wrist pin 20': on; which fis pivotally sie tachedto the upstanding combination lever 22. The piston valve 3l operating in the steam chest 31L in the usual manner controls the admission and exhaust of the steam to and from the cylinders through the ports 32 and 32a. The customary valve rod 24 hasthe rear end thereof provided with a crosshead 24 slidablycarriedyby opposing guides 25 i formed at the rear end of a bracket 26 extendchest head.

ing from and integrally cast with the steam In the Walschaert valve. gear previously mentioned, the combination lever, the valve rod and the radius .rod are non-adjustably connected in a manner not herein disclosed and k.by virtue of such connection, the piston valve is ymaintained set with a non-variable lead', or preadmission,

' ',InFigure l of the drawings, I havevshownl the various Working'parts as 'appearing on the right side of the locomotive but it is tov be understood that. all the parts hereinbefore described with the exception of the tumbling shaft 13, the reach rod and the Weight are duplicated at the remote or left hand Y sidexofjthe locomotive, the tumbling shaft making the connectionbetween the opposite sides and alsothat all suchparts with the exception of the duplicate ofthe arm 14 are nowyin'common use Aand'form part of the V equipmentfof the Walschaert valve gear. In

installing my invention in the VValschaertV valve gear, I Vchange the connection between the valve rod, Lthe radius rod and the combination lever and substitute parts shortlydescribed.` y Y, c In'introducing myy invention,I do not materially alter the design of the valve rodcross- V combination lever 22. f The forked sides of the combination lever provideY opposing vertically extending guides fora link block 36,

the upper end' of which is fitted withay cross pin 37. v,The forward end of the radius rod is centrally and pivotally mounted on thepin 37 and-on the pin 37 I also'mountrotatably the forked lower end 23 of the controllink hanger 23 which has the upper end thereof forked'to span the controllink 38 and the control link.' Y,

forked ends carrying a pin 39 passing centrallythrough the control Ylink block 40 slidably mounted in the arcuate slot 38 of the ',Iothe upper end of the'arm 14, Ipivotally connect a rod'lll which' has the forward end .thereof forked at 42'and; the forks spanning .the control'linkblockand pivotally mounted lon the pin 39. The above arrangement is such that the control link block is directly under the influence of the reach rod 17 and here I wish to explain that the control link 38 is permanently'fastened in any suitable manner to a iixed part of the locomotive body. 'V The various parts of my invention as hereinbefore described are duplicated at the re- Y mote side of the locomotive to that shown and in o order to actuate such duplicate parts in l Vunison With-those shown, vthe remote end .of

the tumbling shaft is provided with an` up- Vstanding arm identical to that 14 and to lwhichis connected pivotally the rear end of the duplicate rod correspondingto that 41.

The radius of the link 38 is chosen in de-` signing thesame with due regard to thelead or pre-admission givenVv the engine valvejon ,V

which thelink is to be used and with the` ob ject of dispensing ywith the lead at the timeV that the engine is to Vbe started and' also of initially quickly returningthe lead -or pre-admission subsequent tostarting and finally slowly returningit until the maximum lead is obtained foreffective and eiicient-running conditions.

According to the. structure disclosed, and considering particularly those addedparts kconstituting my invention, it will be apparent that when the engine isV at a standstill and itis startedpby manipulating the reversing gear in the proper direction, the movement of the reversing gear will effect the customary movements in the ,valve link vmechanism shown and also a movement 1n the control icoV block 40 which carries the controlhanger23.

When the reversing gear is moved to say its extremeforward or rear position, the block Y 40 moves Aaheadorback and in somoving perf mits a dropping of the pin 37 which is conand which in dropping approaches 'the' Vnectedto the forwardend of the radius rod aligned longitudinalaxes of the trunnions35 which are carried by the vrear end ofthe re-y ciprocating valve stem. l The movement vof the pin 37 towards A`the saidVtrunnion-s decreases` the travelof the valve and the limiteddown position' of .thev y pin 37 is designed such that when in suchpo-` sition, the lead or pre-admission given. the

valve is enti-rely rdispensed with and that f when it is in its extreme up' position,;the valve 4has, its maximumrlead as required foreffec-` tive and efficientrunningconditions' of the,YV

. f l ,120 particularly point out alsoin re` ygard toV they link38 that the arrangement is engine. I wishV to such that in the return mo-vement of the'block 40 to its central position, the travel ofthe pin. 37 `in aA direction away from the trunnions Y 35 Vwill be initially quick and then gradually slowed vup, as n it approachesv its uppermost positionand thisis desirable as the; leadVV of y f the valvek is quickly initiallyfrestored.

V`@In the drawings,'I have shown v)the 'well known inside admission Valve and with such type of valve, the curvature of the link 39 is as shown. Should, however, an outside admission valve be used and as quite often occurs in locomotive engines, the link 38 is reversed, that is to say, the centre point of the radius of curvature is above the link instead of below as herein shown.

In this latter arrangement, the forks or X m guides of the combination lever 22 will be sufficiently long to .permit the link block to take a position such that the pin'37 is at all times below the trunnions 35 and such'accordingly requires a rising movement of the hanger 23 to bring the axis of the pin 37 towards the aligned axes of the trunions 35. What I claim as my invention is i. In a locomotive valve gear mechanism, the combination with the forked rear end of the valve rod, the forked upper end of the combination lever pivotally attached to the forked end of the valve rod and the radius rod, of a block mounted between the forked ends of the combination lever and slidably carried g5 thereby to move in a direction radial to the pivot connection between the combination lever and the valve rod, a pivot pin connecting the radius rod to the sliding block, a stationary control link having an arcuate slot therein, a link block slidably mounted in the slot, a hanger having the ends thereof pivotally connected'to theblocks and an operating connection between the control link block and the reach rod of the reversing gear ofthe valve gear mechanism, said control link and associated parts being positioned such that when the reversing gear is moved to its forward or rear positions, the radius rod pivot pin will be moved into axial alinement with w the pivot connection between the valve rod and the combination lever.

Signed at Winnipeg, this 12th day of Oc-- tober, 1928.

JOHN A. COTTON. 

